Fuel cells having electrolyte layers with electrolyte supported in the pores of a porous element, such as electrolyte layers with electrolyte supported in the pores of silica gel, have been disclosed in the past.
When the electrolyte layer is formed by supporting the electrolyte in the pores of the porous carrier, the electrolyte layer must be thick enough to ensure that the electrolyte layer is gas-impermeable (to prevent cross leaking between the fuel gas and oxidizing gas). A problem, however, is that the resistance of the electrolyte layer increases as the thickness increases, resulting in lower cell performance. There is thus a need for a technique to improve cell performance with a thinner electrolyte layer while ensuring that the electrolyte layer is gas-impermeable.